Members of some classes tend to be better at certain types of activities than members of other classes. So for example:
Rogue classes tend to be better at stealth than others.
Mage classes tend to be better at arcane magic than others.
Cleric classes tend to be better at receiving divine aid than others.
Fighter classes tend to be better at the use of unusual melee weapons than others.
Having magic items which work better for those who are better at doing the sorts of things those items help with, makes sense to me.
So for example:
"Elvish Boots: When worn, rogues gain expertise in Dex (move silent) checks, others gain skill proficiency in such checks."
"Wand of Eldritch Rays: Fires a ray of energy at a target within 25', doing 1d6 damage, or 2d6 if fired by a Mage."
"Rod of Healing: This rod heals 1d6 hit points of damage to a target within 25", or 2d6 damage if used by a Cleric."
"Staggering Maul +1: This Maul deals 2d6+1 bludgeoning damage. Targets struck must succeed on a DC15 Constitution save or else are Restrained for 1 round. Fighters wielding this weapon may choose to Stun targets rather than restrain them."
In all of these examples, the item is usable by anyone, but it works better if used by a particular class which is naturally better at the sorts of things that item does.
This is a very good idea.